Page 419 - Small Animal Internal Medicine, 6th Edition

CHAPTER 26 Clinical Manifestations of Gastrointestinal Disorders 391

originating from the esophagus. Radiographs (plain and/or
contrast) or esophagoscopy may reveal a tumor or retained TABLE 26.1
VetBooks.ir food secondary to stricture or weakness. If the history and Aids to Differentiate Regurgitation From Vomiting*
oral examination are unrevealing except for mild to moder-
ate tartar accumulation, the teeth should be cleaned to try to
resolve the problem. SIGN REGURGITATION VOMITING
Drooling is usually caused by nausea, oral pain, or dys- Prodromal No Usually
phagia. The approach to the diagnosis of oral pain and dys- nausea †
phagia is described under the appropriate headings. Nausea Retching ‡ No Usually
is considered in the section on vomiting. Material
Dysphagic animals without demonstrable lesions or pain produced
may have neuromuscular disease. Dysphagia of muscular Food ± ±
origin usually results from atrophic myositis (see Chapter Bile No ±
67). Finding swollen, painful temporal muscles suggests Blood ± (undigested) ± (digested or
acute myositis. Finding severe temporal-masseter muscle undigested)
atrophy plus difficulty opening the mouth (even when the Amount of Any amount Any amount
animal is anesthetized) suggests chronic temporal-masseter material
myositis. Biopsy of affected muscles is indicated. It is critical Time relative to Anytime Anytime
that muscle tissue be retrieved; it is easy to obtain only eating
fibrous scar tissue. A positive test for antibodies to type 2M Distention of Rare No
muscle fibers is consistent with masticatory muscle myositis cervical
but not polymyopathy. esophagus
Neurogenic dysphagia is caused by disorders in the oral Dipstick analysis
(i.e., also called prehensile), pharyngeal, or cricopharyngeal of material
phases of swallowing (disorders of the latter two phases are pH ≥7 ≤5 or ≥8
discussed in the section on regurgitation). Rabies should Bile No ±
always be considered, despite its relative rarity. After rabies
is presumptively ruled out, cranial nerve deficits (especially *These are guidelines that often help distinguish vomiting from
regurgitation. However, occasional animals will require plain and/
deficits of cranial nerves V, VII, IX, XII) should be consid- or contrast-enhanced radiographs to distinguish between the two. In
ered. Because clinical signs vary depending on the nerve particular, animals that are vomiting may appear to be
(or nerves) affected, a careful neurologic examination is regurgitating. The reverse is less common.
indicated. † May include salivation, licking lips, pacing, and an anxious
Inability to pick up food or having food drop from the expression. The owner may simply state that the animal is aware
that it will soon “vomit.”
mouth while eating usually indicates a prehensile disorder. ‡ These are usually forceful, vigorous abdominal contractions or dry
Dysphagia may be noticeable in dogs and cats with pharyn- heaves. This is not to be confused with gagging, which is common
geal and cricopharyngeal dysfunction, but regurgitation is in regurgitation.
often more prominent. Dynamic contrast-enhanced cine-
fluoroscopy or fluoroscopy is best for detecting and defining
neuromuscular dysphagia. Localized myasthenia is an coughing at the time of the event. However, because dogs
important cause of pharyngeal dysphagia and should be that cough and gag excessively may stimulate themselves to
ruled out with serology. If neuromuscular problems are vomit as well, careful history taking is important. Animals
seemingly ruled out by imaging and serology, then anatomic that regurgitate and some that vomit may cough due
lesions and occult causes of pain (e.g., soft tissue inflamma- to aspiration.
tion or infection) must be reconsidered. The criteria in Table 26.1 are guidelines. Some animals
that appear to be regurgitating are vomiting and vice versa.
In particularly severe cases of esophageal weakness, one
DISTINGUISHING REGURGITATION may see the cervical esophagus balloon in and out during
FROM VOMITING FROM respiration (Video 26.1). If the clinician cannot distinguish
EXPECTORATION between two based on history and physical examination
findings, a urine dipstick may be used to determine pH
Regurgitation is expulsion of material (i.e., food, water, and whether there is bilirubin in freshly “vomited” mate-
saliva) from the mouth, pharynx, or esophagus and must rial. If the pH is 5 or less, the material is probably gastric in
be differentiated from vomiting (expulsion of material from origin, resulting from vomiting. A pH of 7 or greater without
the stomach and/or intestines) and expectoration (expul- evidence of bilirubin is most consistent with regurgitation.
sion of material from the respiratory tract). Historical and Finding bilirubin means the material is duodenal in origin
physical examination findings sometimes allow differentia- (i.e., vomiting). Finding blood in the urine dipstick test is
tion (Table 26.1). Expectoration is generally associated with not helpful.